What is the history of Moyamoya?

Moyamoya disease is a rare and progressive cerebrovascular disorder that was first identified in Japan in the 1960s. The term "moyamoya" translates to "puff of smoke" in Japanese, which describes the appearance of the tangled blood vessels that develop in the brain.

The history of moyamoya dates back to 1957 when a Japanese neurosurgeon named Takeuchi and his colleague, Shimizu, encountered a peculiar case of a young girl with recurrent strokes. They discovered abnormal blood vessels in her brain that resembled a "puff of smoke" on angiography. However, it was not until 1969 that Takeuchi coined the term "moyamoya disease" to describe this unique condition.

Initially, moyamoya disease was primarily observed in Japan, where it gained recognition as a distinct clinical entity. The prevalence of moyamoya in Japan is estimated to be around 1 in 100,000 individuals. However, over time, cases of moyamoya have been reported worldwide, including in North America, Europe, and other Asian countries.

The exact cause of moyamoya disease remains unknown, although several theories have been proposed. Some researchers believe that genetic factors play a significant role, as familial cases of moyamoya have been reported. In fact, certain gene mutations have been identified in individuals with moyamoya, suggesting a genetic predisposition to the disease. However, the majority of moyamoya cases are sporadic, with no family history.

Moyamoya disease primarily affects children and young adults, with a peak incidence between the ages of 5 and 10. It is more prevalent in females than males. The disease is characterized by the progressive narrowing and eventual occlusion of the internal carotid arteries, which are major blood vessels supplying the brain. As a result, the brain compensates by developing a network of tiny collateral blood vessels, known as moyamoya vessels, to bypass the blocked arteries.

The clinical presentation of moyamoya disease varies depending on the age of onset and the severity of blood vessel involvement. Common symptoms include recurrent transient ischemic attacks (TIAs), strokes, and seizures. Children may also experience cognitive decline, developmental delays, and neurological deficits.

Diagnosing moyamoya disease involves a combination of clinical evaluation, neuroimaging, and angiography. Magnetic resonance imaging (MRI) and computed tomography (CT) scans can reveal characteristic findings such as narrowed blood vessels and the presence of moyamoya vessels. Cerebral angiography, the gold standard for diagnosis, involves injecting a contrast dye into the blood vessels to visualize the extent of arterial narrowing and the formation of collateral vessels.

Treatment for moyamoya disease aims to improve blood flow to the brain and prevent further strokes. The mainstay of treatment is surgical revascularization, which involves creating new blood vessels to bypass the blocked arteries. The two most common surgical procedures are direct bypass, where a healthy blood vessel is connected directly to the brain's blood vessels, and indirect bypass, where a blood vessel is redirected to increase blood flow to the brain.

In recent years, advancements in understanding moyamoya disease have led to improved diagnosis and treatment options. Ongoing research continues to unravel the underlying mechanisms of the disease and explore potential genetic and environmental factors that contribute to its development.